Bioequivalence and Bioavailability Forum • adjusted alpha = 0.045

adjusted alpha = 0.045 [Two-Stage / GS Designs]

posted by d_labes – Berlin, Germany, 2012-08-03 13:33 (5078 d 14:38 ago) – Posting: # 9029
Views: 17,669

Dear Helmut!

Very well elaborated post. THX.

❝ It’s also clear from the table that in some scenarios α_emp. was substantially below 0.05 – indicating that 0.0294 was lower than necessary. Of course no problems with risk I, but the penalty one has to pay in terms of the sample size is too high. See for example α_emp. for n₁ 12, CV_intra 10%: Method C 0.0496, D 0.0498, but B 0.0297…

❝ In other words, if you opt for Method B in this scenario you could increase α_adj. and still maintain α_emp. ≤0.05. For α_adj. 0.045 (!), Method B, 10⁶ simulations I got α_emp. 0.04501 and 1–β_emp. 98.69%. In this case (only ~1% of studies went to stage 2), the penalty in Method B is too high.

Wow! Cough :smoke:

... Very interesting result.
Where did the α_adj.=0.045 came from? Luckily guess? Or some Hermetism?

—
Regards,

Detlew

Complete thread:

two-stage design power 90% second stage Yvonne 2012-08-02 09:50 [Two-Stage / GS Designs]
- two-stage design power 90% second stage ElMaestro 2012-08-02 10:17
  - two-stage design power 90% second stage Yvonne 2012-08-02 11:47
    - two-stage design power 90% second stage ElMaestro 2012-08-02 11:54
- two-stage design power 90% in sample size adaption d_labes 2012-08-02 10:33
  - two-stage design power 90% in sample size adaption ElMaestro 2012-08-02 11:29
    - two-stage design power 90% in sample size adaption Yvonne 2012-08-02 12:06
      - two-stage design power 90% in sample size adaption ElMaestro 2012-08-02 16:59
- Are simulations sufficient? …lenghty post! Helmut 2012-08-02 17:39
  - adjusted alpha = 0.045d_labes 2012-08-03 11:33
    - adjusted alpha = 0.038 Helmut 2012-08-03 14:26
      - adjusted alpha by sims? d_labes 2012-08-03 15:48
        
        Yeah but, no but, yeah but, no but… Helmut 2012-08-03 16:39
        
        Yeah but, no but ... d_labes 2012-08-07 14:42
        
        Yeah but, no but ... Helmut 2012-08-07 15:14